Mowin8603

ok this is really weird to me and im not really good with wireing. but the problem is is my 87' GT always seems to have low volts, like while im driving it with the heat on and the head lights it has a hard time staying out of the red on the gauge. but during the day while i dont have the heat or the lights on its fine, it stays just under the middle dash on the gauge. now im sure your thinking that the atl is crappin out, ya i thought that to.. had it checked and its fine. just put a new battery in it to like a week ago. my dad says that i have what he calls a "dead short" somewhere and thats whats draining it. but i can leave the car overnight or not drive it all day and then get in it and itll be fine. its just when the car is running and i have a lot of accessories on and it stays at idle for a while, it seems like the alt cant keep up. the car does have underdrive pulleys and i have the stockers, so im going to put those on tomarrow and see if it makes a difference, but it looks to me like the stock alt pulley is still on the car.. all this is just really weird to me because i cant think of anything else that could be wrong other than the underdrive pulleys? anyone got any ideas what else this might be so that i can check it out after i change the pulleys tomarrow?[/align][/align]oh heres an example of how the car is acting: i got in it today, started up just fine and was actually a notch or two above the middle on the volts gauge. drove it around started it a another time or two, everything was ok. then it got dark out, i got hungry and went to the choke and puke and idled a little while in the drive up with the lights and the heat on and i noticed the gauge ended up in the red. still ran fine, just when i shut it off it didnt have enough to start back up. so i jumped it and then shut it off after a lil driving and then couldnt start again. so im thinking the alt just cant charge the battery back up and keep up with the accessories at the same time with the underdrive pulleys on the car... any other ideas??[/align]

Mowin8603

anyone???

frdmstng1986GT

is the alt pulley that is on the car bigger or smaller then the one that isnt on the car?

Li0nHart

does the volt meter get out of the red when you rev up to 4 grand?

Mowin8603

and the pulley on the car right now is bigger than the one that came with the car in a box of other stuff. but i do have the other stock pulleys in a box that came with the car.[/align][/align]ya itll get out of the redat 3 grand[/align]

frdmstng1986GT

i am willing to bet the underdrive pulley for the alt is on it.

Mowin8603

ok.. i might just be thinking to hard about this or something, but underdrive pulleys are smaller than stock correct? including the alt pulley? [/align][/align]and if the pulley on the alt is smaller shouldnt it turn faster??? therfore speed up the alt and make it more efficient? ..or am i way off?[/align] [/align][/align]EDIT: but either way here.. shouldnt putting the stock pulleys back on fix this? and if the alt pulley is bigger than the one that came in the box, i should leave it on the car correct?[/align]

Li0nHart

i'd probably never put an underdrive pully on the alt..other people have their opinions on it but i just wouldn't recommend it...an under voltage state is hard an the electronics, battery, alt..etc.

frdmstng1986GT

yes,underdrive pulleys are a little smaller. the bigger the pulley thefaster it will spin.

Mowin8603

ok so.. i should put the smaller alt pulley on it??[/align][/align]and if the pulleys i have in this box that came with the car are smaller than the ones on it (being the underdrive pulleys) then i should put those on to, to be safe?[/align]